Development of simple and rapid LC–MS/MS method for determination of celecoxib in human plasma and its application to bioequivalence study

A suitable liquid chromatography tandem mass spectrometry (LC–MS/MS) method to determine celecoxib in human plasma is needed for bioequivalence and pharmacokinetic studies of celecoxib preparations. The present study describes a simple, rapid, reproducible, and reliable LC–MS/MS method to determine celecoxib concentrations in human plasma. After one-step liquid–liquid extraction (LLE) using methyl tert-butyl ether (MTBE), celecoxib and atorvastatin (internal standard, IS) were eluted on a Luna HILIC column with an isocratic mobile phase, consisting of 10 mM ammonium formate buffer (adjusted to pH 3.0 with formic acid):methanol (5:95, v/v) at a flow rate of 0.2 mL/min. The achieved lower limit of quantitation (LLOQ) was 10 ng/mL (S/N > 10) and the standard calibration curve for celecoxib was linear (correlation coefficients were >0.9995) over the studied concentration range (10–2000 ng/mL). The inter- and intra-assay coefficients of variation ranged from 1.15% to 4.93% and 1.08% to 7.81%, respectively. The chromatographic run time for each plasma sample was <2 min. The developed method was successfully applied to a bioequivalence study of celecoxib in healthy Korean male volunteers.